Wireless communication over a transducer device

• US 7,574,173 B2
• Filed: 10/06/2006
• Issued: 08/11/2009
• Est. Priority Date: 03/16/2001
• Status: Expired due to Term

• Current Assignee: Freelinc Holdings, LLC
• Original Assignee: Radeum, Inc.
• Inventors: Terranova, Domenic F., Palermo, Vincent
• Primary Examiner(s): ZEWDU, MELESS NMN
• Application Number:
  US11/544,950
• Publication Number:
  US 20070082611A1
• Time in Patent Office: 1,040 Days
• Field of Search: 455/562.1, 455/569.1, 455/507, 455/517, 455/129, 455/465, 455120-126, 455 87- 88, 455 68- 69, 455 77- 78, 455/62, 455/80, 455/67.13, 455/67.11, 455/3.01, 455/3.05, 455/63.1, 455 411- 413, 455/575.2, 455/63.4, 455/107, 4551271-1272, 4551931-1932, 455/550.1, 455/575.7, 34031015-31017, 340/448, 340/941, 340/538.14, 340/854.8, 34087031-87032, 340/531, 34053815-53816, 340/870.37, 367/140, 367/176, 367/912, 343750-751, 343/764, 343/842, 343/855, 343/861, 343/907
• US Class Current: 455/41.1
• CPC Class Codes: H04B 5/22 Capacitive coupling
• CPC Class Codes: H04B 5/26 using coils
• CPC Class Codes: H04B 5/48 Transceivers
• CPC Class Codes: H04M 1/6041 Portable telephones adapted for handsfree use
• CPC Class Codes: H04M 1/6066 including a wireless connection
• CPC Class Codes: H04M 1/727 Identification code transfer arrangements
• CPC Class Codes: H04M 1/737 Characterised by transmission of electromagnetic waves other than radio waves, e.g. infrared waves
• CPC Class Codes: H04R 2420/07 Applications of wireless loudspeakers or wireless microphones

Abstract

One aspect of the present invention is generally directed towards a system and method of tuning a transducer for transmitting and receiving a wireless signal. In an illustrative embodiment, a single transducer is coupled to a first or second circuit for either transmitting or receiving, respectively. Generally, electrical characteristics of the first circuit are adjusted to increase a magnetic field generated by the transducer. Conversely, electrical characteristics of the second circuit are adjusted to increase a signal generated by the transducer for receiving a magnetic field. Accordingly, a single transducer device can be tuned for either transmitting or receiving a corresponding wireless signal.

Claims

1. A method for supporting inductive communication, the method comprising:

coupling at least one transducer to one of a selected first circuit for transmitting and a selected second circuit for receiving, wherein the at least one transducer is selectively coupled to a transmitter via the first circuit and the at least one transducer is selectively coupled to a receiver via the second circuit;

if the first circuit is coupled to the at least one transducer, adjusting electrical characteristics of the first circuit to increase a magnetic field generated by the at least one transducer; and

if the second circuit is coupled to the at least one transducer, adjusting electrical characteristics of the second circuit to increase a signal generated by the at least one transducer.

2. The method as in claim 1, wherein the electrical characteristics of the first and second circuits are adjusted using passive circuit components.

3. The method as in claim 1 further comprising:

transmitting a magnetic field over the at least one transducer when the at least one transducer is coupled to the first circuit; and

receiving a magnetic field over the at least one transducer when the at least one transducer is coupled to the second circuit.

4. The method as in claim 1 further comprising:

adjusting a capacitance of the first circuit to reduce an effective impedance of the at least one transducer for transmitting; and

adjusting a capacitance of the second circuit to increase an effective impedance of the at least one transducer for receiving.

5. The method as in claim 1 further comprising:

switching the coupling of the at least one transducer between the first and second circuits to support bidirectional time division multiplexed communication with a transceiver at a remote location.

6. The method as in claim 1, wherein the electrical characteristics of the first circuit are adjusted to achieve an efficient coupling between the at least one transducer and the transmitter and the electrical characteristics of the second circuit are adjusted to achieve an efficient coupling between the at least one transducer and the receiver.

7. The method as in claim 1 further comprising:

adjusting a reactance of the first circuit to transmit a magnetically encoded signal at a first carrier frequency; and

adjusting characteristics of the second circuit to receive a magnetically encoded signal at a second carrier frequency.

8. The method as in claim 1 further comprising:

disposing an inductive element in the second circuit, the inductive element having an approximate inductance as that of the at least one transducer.

9. The method as in claim 1, wherein the second circuit includes at least a portion of the first circuit that is coupled via a switch.

10. The method as in claim 1, wherein the first circuit serially tunes the at least one transducer for transmitting over the at least one transducer and the second circuit parallel tunes the at least one transducer for receiving over the at least one transducer.

11. A method for supporting inductive communication, the method comprising:

switching to select one of transmitting and receiving over at least one transducer;

via a first circuit, effectively tuning the at least one transducer to be a low impedance device for generating a magnetic field when a transmitter is switched to transmit over the at least one transducer, wherein when the transmitter is switched to transmit over the at least one transducer, the transmitter is coupled to the at least one transducer via the first circuit;

via a second circuit, effectively tuning the at least one transducer to be a high impedance device for receiving a magnetic field when a receiver is switched to receive over the at least one transducer, wherein when the receiver is switched to receive over the at least one transducer, the receiver is coupled to the at least one transducer via the second circuit.

12. The method as in claim 11 wherein the first circuit is serially tuned for transmitting over the at least one transducer and the second circuit is parallel tuned for receiving over the at least one transducer.

13. The method as in claim 11 further comprising:

in a transmitting mode, reducing an overall reactance of the first circuit including the at least one transducer by substantially matching an inductance of the at least one transducer with a capacitance provided by the first circuit.

14. The method as in claim 11 further comprising:

via switching, decoupling the transmitter from the first circuit and the at least one transducer, and coupling the receiver and portion of the second circuit to the first circuit and the at least one transducer.

15. The method as in claim 11 further comprising:

from the transmitter, generating an output at one of two voltages that is coupled to drive the at least one transducer.

16. The method as in claim 11 further comprising:

disposing a resistance in series with the at least one transducer.

17. The method as in claim 11 further comprising:

tuning a combined impedance of the first circuit and the at least one transducer for maximal magnetic power output of the at least one transducer at a particular carrier frequency.

18. The method as in claim 11 further comprising:

adjusting an impedance of the first and second circuit to transmit and receive over the at least one transducer at a substantially similar carrier frequency.

19. The method as in claim 11 further comprising:

varying inductive characteristics of the at least one transducer to adjust a combined impedance of the first circuit and the at least one transducer.

20. The method as in claim 11 further comprising:

adjusting a reactance of the first or second circuits by switching selected capacitors of a capacitor bank.